This proposal aims at investigating the biosynthesis of procollagen and its maturation into finished tropocollagen molecules in a variety of cells whose common feature is that they produce an extracellular collagenous matrix. To this end we intend to establish in cell culture, clonal lines from normal, diseased, and malignant tissues from a variety of sources, primarily from mice whose genetics are well characterized. Isolation and characterization of procollagen in conjunction with biological studies will enable us to better understand how errors in synthesis or maturation of procollagen are manifested as heritable connective tissue disorders.